The 4″ back up pads with a central locating button are designed for use with 100mm surface conditioning discs.
SCM discs are supplied with a 10mm centre hole which allows for simple location on the back up pad. The location pin eliminates disc vibration and improves surface conditioning disc life as well as reducing back up pad wear.
For centralising surface conditioning discs on 100mm / 4″” angle grinders without risk of damaging the workpiece